/**
 * Copyright (c) 2008, Piercarlo Slavazza
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * The name of Piercarlo Slavazza cannot be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY Piercarlo Slavazza ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL Piercarlo Slavazza BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.libapml.indexer;

import java.io.IOException;
import java.util.Set;

import org.apache.lucene.analysis.standard.StandardAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.document.Field.Index;
import org.apache.lucene.document.Field.Store;
import org.apache.lucene.index.CorruptIndexException;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.LockObtainFailedException;

import com.libapml.util.Helper;

public class LuceneWriter {

	public static final String DOC_URI_FIELD = "uri";
	
	private Directory luceneDirectory;
	
	private IndexWriter writer;
	
	/**
	 * 
	 * @param luceneDirectory
	 * @param stopwords may be null
	 * @throws CorruptIndexException
	 * @throws LockObtainFailedException
	 * @throws IOException
	 */
	@SuppressWarnings("unchecked")
	protected LuceneWriter(Directory luceneDirectory, Set stopwords) throws CorruptIndexException, LockObtainFailedException, IOException {
		
		Helper.checkNotNull(luceneDirectory);
		
		this.luceneDirectory = luceneDirectory;
		
		writer = new IndexWriter(
				luceneDirectory, 
				(stopwords != null ? new StandardAnalyzer(stopwords) : new StandardAnalyzer()) ,
				//new NGramAnalyzer(stopwords, 2),
				//new NGramAnalyzer(2),
				true);
		
	}

	public Directory getLuceneDirectory() {
		return luceneDirectory;
	}
	
	public void add(ApmlDocument document) throws CorruptIndexException, IOException {
		
		Document luceneDocument = new Document();
		
		luceneDocument.add(new Field(
				"contents", 
				document.content,
				Store.NO,
				Index.TOKENIZED,
				Field.TermVector.YES));
		
		luceneDocument.add(new Field(
				DOC_URI_FIELD, 
				document.uri.toString(), 
				Field.Store.YES, Field.Index.UN_TOKENIZED));
		
		writer.addDocument(luceneDocument);
		
	}
	
	public void close() throws CorruptIndexException, IOException {
		
		writer.close();
		
	}
	
}
